EXPERIMENTAL INVESTIGATION OF BRAKING DYNAMICS OF ELECTRIC VEHICLE

One of the most distinctive features of brake architecture for hybrid and full electric vehicles is an embedded function of brake blending, i.e. a possibility to activate either the electric braking or conventional friction brakes depending on the actual dynamic state of the vehicle. Development of the brake blending control requires complex modelling and experimental studies using diverse software tools and testing equipment. Within this context, the paper relates to such important topics like (i) experimental estimation of brake system dynamics and (ii) assessment of parameters characterizing the brake blending. The investigation of the brake characteristics relevant to the brake blending has been realized by the use of the experimental platform including a complex hardware-in-the-loop (HIL) test rig to investigate dynamic processes in hydraulic and electro-hydraulic brake systems and an integrated environment connecting the hardware brake components with the software-based vehicle simulator. The proposed experimental platform consists of the following elements:  Brake system hardware (both the conventional layout and the decoupled brake-by-wire layout);  Brake robot to control the brake pedal with alterable actuation dynamics;  dSpace real-time components;  Computer simulator of the vehicle and vehicle manoeuvres in IPG CarMaker Software. The case study introduced in the paper has been performed for the test programme aimed at the definition of the dynamic characteristics of the brake system by the different velocities of the brake pedal actuation. The obtained results give a basis for (i) comparison of base brake functions of conventional and decoupled brake systems and (ii) analysis of brake actuation dynamics on the brake blending. The obtained results as well as developed experimental technique can find a proper application for advanced strategies of brake control of electric vehicles with simultaneous improving of the driver comfort and brake performance.